debhelper

package: debhelper

title: debhelper(7)

summary: the debhelper tool suite

text:
# debhelper(7)

## NAME
debhelper - the debhelper tool suite

## SYNOPSIS
dh_* [-v] [-a] [-i] [--no-act] [-ppackage] [-Npackage] [-Ptmpdir]

## DESCRIPTION
Debhelper is used to help you build a Debian package. The philosophy behind debhelper is to provide a collection of small, simple, and easily understood tools that are used in debian/rules to automate various common aspects of building a package. This means less work for you, the packager. It also, to some degree means that these tools can be changed if Debian policy changes, and packages that use them will require only a rebuild to comply with the new policy.

A typical debian/rules file that uses debhelper will call several debhelper commands in sequence, or use dh(1) to automate this process. Examples of rules files that use debhelper are in /usr/share/doc/debhelper/examples/

To create a new Debian package using debhelper, you can just copy one of the sample rules files and edit it by hand. Or you can try the dh-make package, which contains a dh_make command that partially automates the process. For a more gentle introduction, the maint-guide Debian package contains a tutorial about making your first package using debhelper.

Except where the tool explicitly denotes otherwise, all of the debhelper tools assume that they run from the root directory of an unpacked source package. This is so they can locate files like debian/control when needed.

## DEBHELPER COMMANDS
Here is the list of debhelper commands you can use. See their man pages for additional documentation.

dh_assistant(1)

tool for supporting debhelper tools and provide introspection

dh_auto_build(1)

automatically builds a package

dh_auto_clean(1)

automatically cleans up after a build

dh_auto_configure(1)

automatically configure a package prior to building

dh_auto_install(1)

automatically runs make install or similar

dh_auto_test(1)

automatically runs a package's test suites

dh_bugfiles(1)

install bug reporting customization files into package build directories

dh_builddeb(1)

build Debian binary packages

dh_clean(1)

clean up package build directories

dh_compress(1)

compress files and fix symlinks in package build directories

dh_computeautosubstvars(1)

compute substvars relevant to most packages

dh_dwz(1)

optimize DWARF debug information in ELF binaries via dwz

dh_fixperms(1)

fix permissions of files in package build directories

dh_gencontrol(1)

generate and install control file

dh_icons(1)

Update caches of Freedesktop icons

dh_install(1)

install files into package build directories

dh_installalternatives(1)

install declarative alternative rules

dh_installcatalogs(1)

install and register SGML Catalogs

dh_installchangelogs(1)

install changelogs into package build directories

dh_installcron(1)

install cron scripts into etc/cron.*

dh_installdeb(1)

install files into the DEBIAN directory

dh_installdebconf(1)

install files used by debconf in package build directories

dh_installdirs(1)

create subdirectories in package build directories

dh_installdocs(1)

install documentation into package build directories

dh_installemacsen(1)

register an Emacs add on package

dh_installexamples(1)

install example files into package build directories

dh_installgsettings(1)

install GSettings overrides and set dependencies

dh_installifupdown(1)

install if-up and if-down hooks

dh_installinfo(1)

install info files

dh_installinit(1)

install service init files into package build directories

dh_installinitramfs(1)

install initramfs hooks and setup maintscripts

dh_installlogcheck(1)

install logcheck rulefiles into etc/logcheck/

dh_installlogrotate(1)

install logrotate config files

dh_installman(1)

install man pages into package build directories

dh_installmenu(1)

install Debian menu files into package build directories

dh_installmime(1)

install mime files into package build directories

dh_installmodules(1)

register kernel modules

dh_installpam(1)

install pam support files

dh_installppp(1)

install ppp ip-up and ip-down files

dh_installsystemd(1)

install systemd unit files

dh_installsystemduser(1)

install systemd unit files

dh_installsysusers(1)

install and integrates systemd sysusers files

dh_installtmpfiles(1)

install tmpfiles.d configuration files

dh_installudev(1)

install udev rules files

dh_installwm(1)

register a window manager

dh_installxfonts(1)

register X fonts

dh_link(1)

create symlinks in package build directories

dh_lintian(1)

install lintian override files into package build directories

dh_listpackages(1)

list binary packages debhelper will act on

dh_makeshlibs(1)

automatically create shlibs file and call dpkg-gensymbols

dh_md5sums(1)

generate DEBIAN/md5sums file

dh_missing(1)

check for missing files

dh_movefiles(1)

move files out of debian/tmp into subpackages

dh_movetousr(1)

canonicalize location according to merged-/usr

dh_perl(1)

calculates Perl dependencies and cleans up after MakeMaker

dh_prep(1)

perform cleanups in preparation for building a binary package

dh_shlibdeps(1)

calculate shared library dependencies

dh_strip(1)

strip executables, shared libraries, and some static libraries

dh_systemd_enable(1)

enable/disable systemd unit files

dh_systemd_start(1)

start/stop/restart systemd unit files

dh_testdir(1)

test directory before building Debian package

dh_testroot(1)

ensure that a package is built with necessary level of root permissions

dh_ucf(1)

register configuration files with ucf

dh_update_autotools_config(1)

Update autotools config files

dh_usrlocal(1)

migrate usr/local directories to maintainer scripts

### Deprecated Commands
A few debhelper commands are deprecated and should not be used.

dh_installmanpages(1)

old-style man page installer (deprecated)

### Other Commands
If a program's name starts with dh_, and the program is not on the above lists, then it is not part of the debhelper package, but it should still work like the other programs described on this page.

## DEBHELPER CONFIG FILES
Many debhelper commands make use of files in debian/ to control what they do. Besides the common debian/changelog and debian/control, which are in all packages, not just those using debhelper, some additional files can be used to configure the behavior of specific debhelper commands. These files are typically named debian/package.foo (where package of course, is replaced with the package that is being acted on).

For example, dh_installdocs uses files named debian/package.docs to list the documentation files it will install. See the man pages of individual commands for details about the names and formats of the files they use. Generally, these files will list files to act on, one file per line. Some programs in debhelper use pairs of files and destinations or slightly more complicated formats.

Note if there is only one binary package listed in debian/control, then debhelper will use debian/foo when there's no debian/package.foo file. In compat levels before compat 15, this fallback also occurs for the first binary package listed in debian/control when there are multiple binary packages. However, it is often a good idea to keep the package. prefix as it is more explicit and also required when upgrading to compat 15.

Additionally, there are some special cases where debhelper will always fallback to a prefix-less version. These are cases such as debian/copyright and debian/changelog, where the files are generally used and needed for all binary packages.

In some rare cases, you may want to have different versions of these files for different architectures or OSes. If files named debian/package.foo.ARCH or debian/package.foo.OS exist, where ARCH and OS are the same as the output of "dpkg-architecture -qDEB_HOST_ARCH" / "dpkg-architecture -qDEB_HOST_ARCH_OS", then they will be used in preference to other, more general files.

Mostly, these config files are used to specify lists of various types of files. Documentation or example files to install, files to move, and so on. When appropriate, in cases like these, you can use standard shell wildcard characters (? and * and [..] character classes) in the files. You can also put comments in these files; lines beginning with # are ignored.

The syntax of these files is intentionally kept very simple to make them easy to read, understand, and modify.

### Substitutions in debhelper config files
In compatibility level 13 and later, it is possible to use simple substitutions in debhelper config files for the following tools:

- dh_clean

- dh_install

- dh_installcatalogs

- dh_installdeb

- dh_installdirs

- dh_installdocs

- dh_installexamples

- dh_installinfo

- dh_installman

- dh_installwm

- dh_link

- dh_missing

- dh_ucf

All substitution variables are of the form ${foo} and the braces are mandatory. Variable names are case-sensitive and consist of alphanumerics (a-zA-Z0-9), hyphens (-), underscores (_), and colons (:). The first character must be an alphanumeric.

If you need a literal dollar sign that cannot trigger a substitution, you can either use the ${Dollar} substitution or the sequence ${}.

The following expansions are available:

DEB_HOST_*, DEB_BUILD_*, DEB_TARGET_*

Expands to the relevant dpkg-architecture(1) value (similar to dpkg-architecture -qVARIABLE_HERE). When in doubt, the DEB_HOST_* variant is the one that will work both for native and cross builds.

For performance reasons, debhelper will attempt to resolve these names from the environment first before consulting dpkg-architecture(1). This is mostly mentioned for completeness as it will not matter for most cases.

Dollar

Expands to a single literal $-symbol. This symbol will never be considered part of a substitution variable. That is:

```
   # Triggers an error
   ${NO_SUCH_TOKEN}
   # Expands to the literal value "${NO_SUCH_TOKEN}"
   ${Dollar}{NO_SUCH_TOKEN}

```

This variable equivalent to the sequence ${} and the two can be used interchangeably.

Newline, Space, Tab

Expands to a single ASCII newline, space and tab respectively. This can be useful if you need to include a literal whitespace character (e.g. space) where it would otherwise be stripped or used as a separator.

env:NAME

Expands to the environment variable NAME. The environment variable must be set (but can be set to the empty string).

Note that all variables must expand to a defined value. As an example, if debhelper sees ${env:FOO}, then it will insist that the environment variable FOO is set (it can be set to the empty string).

Substitution limits

To avoid infinite loops and resource exhaustion, debhelper will stop with an error if the token contains many substitution variables (50) or the total size of the expanded value exceed a certain size (4096 characters or 3x length of the original input - whichever is bigger).

Note the limit is per token. Every helper decides its own definition of a token. The common case of files like debian/package.install, each token is a file/path name.

Substitution limitations: filtering

The built-in substitution cannot be used to "filter" out content. Attempts to create "comments" or "empty lines" via substitution will result in those variables being considered a token in its own right with the content given.

If you want filtering, consider using an executable debhelper config file with dh-exec as interpreter. The dh-exec tool supports several features out of the box. Though keep in mind that dh-exec has its own substitution logic that can feature interact with the one from debhelper.

### Executable debhelper config files
If you need additional flexibility, many of the debhelper tools (e.g. dh_install(1)) support executing a config file as a script.

To use this feature, simply mark the config file as executable (e.g. chmod +x debian/package.install) and the tool will attempt to execute it and use the output of the script. In many cases, you can use dh-exec(1) as interpreter of the config file to retain most of the original syntax while getting the additional flexibility you need.

When using executable debhelper config files, please be aware of the following:

- The executable config file must exit with success (i.e. its return code should indicate success).

- In compatibility level 13+, the output will be subject to substitutions (see "Substitutions in debhelper config files") where the tool support these. Remember to be careful if your generator also provides substitutions as this can cause unnecessary confusion. Notably, the commonly used dh-exec tool has its own substitution support. Otherwise, the output will be used exactly as-is. Notably, debhelper will not expand wildcards or strip comments or strip whitespace in the output it reads. The dh-exec tool has an output filter on by default that will prune these things out.

If you need the package to build on a file system where you cannot disable the executable bit, then you can use dh-exec(1) and its strip-output script.

## SHARED DEBHELPER OPTIONS
The following command line options are supported by all debhelper programs.

-v, --verbose

Verbose mode: show commands that modify the package build directory. Note that verbose mode may also output other "internal" commands that do not directly affect the package build directory.

--no-act

Do not really do anything. If used with -v, the result is that the command will output what it would have done.

-a, --arch

Act on architecture dependent packages that should be built for the DEB_HOST_ARCH architecture.

-i, --indep

Act on all architecture independent packages.

-ppackage, --package=package

Act on the package named package. This option may be specified multiple times to make debhelper operate on a given set of packages.

-s, --same-arch

Deprecated alias of -a. This option is removed in compat 12.

-Npackage, --no-package=package

Do not act on the specified package even if an -a, -i, or -p option lists the package as one that should be acted on.

--remaining-packages

Do not act on the packages which have already been acted on by this debhelper command earlier (i.e. if the command is present in the package debhelper log). For example, if you need to call the command with special options only for a couple of binary packages, pass this option to the last call of the command to process the rest of packages with default settings.

-Ptmpdir, --tmpdir=tmpdir

Use tmpdir for package build directory. The default is debian/package

--mainpackage=package

Deprecated: This option has no practical use in compat 15 or later as the behaviour it affects is removed in compat 15. This little-used option changes the package which debhelper considers the "main package", that is, the first one listed in debian/control, and the one for which debian/foo files can be used instead of the usual debian/package.foo files.

-O=option|bundle

This is used by dh(1) when passing user-specified options to all the commands it runs. If the command supports the specified option or option bundle, it will take effect. If the command does not support the option (or any part of an option bundle), it will be ignored.

## COMMON DEBHELPER OPTIONS
The following command line options are supported by some debhelper programs. See the man page of each program for a complete explanation of what each option does.

-n

Do not modify postinst, postrm, etc. scripts.

-Xitem, --exclude=item

Exclude an item from processing. This option may be used multiple times, to exclude more than one thing. The item is typically part of a filename, and any file containing the specified text will be excluded.

-A, --all

Makes files or other items that are specified on the command line take effect in ALL packages acted on, not just the first.

## BUILD SYSTEM OPTIONS
The following command line options are supported by all of the dh_auto_* debhelper programs. These programs support a variety of build systems, and normally heuristically determine which to use, and how to use them. You can use these command line options to override the default behavior. Typically these are passed to dh(1), which then passes them to all the dh_auto_* programs.

-Sbuildsystem, --buildsystem=buildsystem

Force use of the specified buildsystem, instead of trying to auto-select one which might be applicable for the package. Pass none as buildsystem to disable auto-selection.

-Ddirectory, --sourcedir=directory, --sourcedirectory=directory

Assume that the original package source tree is at the specified directory rather than the top level directory of the Debian source package tree. Warning: The --sourcedir variant matches a similar named option in dh_install and dh_missing (etc.) for historical reasons. While they have a similar name, they have very distinct purposes and in some cases it can cause errors when this variant is passed to dh (when then passes it on to all tools).

-B[directory], --builddir[=directory], --builddirectory[=directory]

Enable out of source building and use the specified directory as the build directory. If directory parameter is omitted, a default build directory will be chosen. If this option is not specified, building will be done in source by default unless the build system requires or prefers out of source tree building. In such a case, the default build directory will be used even if --builddirectory is not specified.

If the build system prefers out of source tree building but still allows in source building, the latter can be re-enabled by passing a build directory path that is the same as the source directory path.

--parallel, --no-parallel

Control whether parallel builds should be used if underlying build system supports them. The number of parallel jobs is controlled by the DEB_BUILD_OPTIONS environment variable ("Debian Policy, section 4.9.1") at build time. It might also be subject to a build system specific limit. If neither option is specified, debhelper currently defaults to --parallel in compat 10 (or later) and --no-parallel otherwise.

As an optimization, dh will try to avoid passing these options to subprocesses, if they are unnecessary and the only options passed. Notably this happens when DEB_BUILD_OPTIONS does not have a parallel parameter (or its value is 1).

--max-parallel=maximum

This option implies --parallel and allows further limiting the number of jobs that can be used in a parallel build. If the package build is known to only work with certain levels of concurrency, you can set this to the maximum level that is known to work, or that you wish to support. Notably, setting the maximum to 1 is effectively the same as using --no-parallel.

--reload-all-buildenv-variables

By default, dh(1) will compute several environment variables (e.g. by using dpkg-buildflags(1)) and cache them to avoid having all dh_auto_* tool recompute them. When passing this option, the concrete dh_auto_* tool will ignore the cache from dh(1) and retrigger a rebuild of these variables. This is useful in the very rare case where the package need to do multiple builds but with different ...FLAGS options. A concrete example would be needing to change the -O parameter in CFLAGS in the second build:

```
    export DEB_CFLAGS_MAINT_APPEND=-O3
    %:
        dh $@
    override_dh_auto_configure:
        dh_auto_configure -Bbuild-deb ...
        DEB_CFLAGS_MAINT_APPEND=-Os dh_auto_configure \
           --reload-all-buildenv-variables -Bbuild-udeb ...

```

Without --reload-all-buildenv-variables in the second call to dh_auto_configure(1), the change in DEB_CFLAGS_MAINT_APPEND would be ignored as dh_auto_configure(1) would use the cached value of CFLAGS set by dh(1).

This option is only available with debhelper (>= 12.7~) when the package uses compatibility level 9 or later.

--list, -l

List all build systems supported by debhelper on this system. The list includes both default and third party build systems (marked as such). Also shows which build system would be automatically selected, or which one is manually specified with the --buildsystem option.

## COMPATIBILITY LEVELS
From time to time, major non-backwards-compatible changes need to be made to debhelper, to keep it clean and well-designed as needs change and its author gains more experience. To prevent such major changes from breaking existing packages, the concept of debhelper compatibility levels was introduced. You must tell debhelper which compatibility level it should use, and it modifies its behavior in various ways.

In current debhelper, you can specify the compatibility level in debian/control by adding a Build-Depends on the debhelper-compat package. For example, to use v13 mode, ensure debian/control has:

```
  Build-Depends: debhelper-compat (= 13)
```

This also serves as an appropriate versioned build dependency on a sufficient version of the debhelper package, so you do not need to specify a separate versioned build dependency on the debhelper package unless you need a specific point release of debhelper (such as for the introduction of a new feature or bugfix within a compatibility level).

Note that debhelper does not provide debhelper-compat for experimental or beta compatibility levels; packages experimenting with those compatibility levels should put the compat level in the X-DH-Compat field of the Source stanza of the debian/control file (or, if only for selected commands, the DH_COMPAT environment variable).

Historically, debhelper required specifying the compatibility level in the file debian/compat, and debhelper up to version 14 supports this for backward compatibility. To use this method, the debian/compat file should contain the compatibility level as a single number, and no other content. If you specify the compatibility level by this method, your package will also need a versioned build dependency on a version of the debhelper package equal to (or greater than) the compatibility level your package uses. So, if you specify compatibility level 13 in debian/compat, ensure debian/control has:

```
  Build-Depends: debhelper (>= 13~)
```

Note that you must use exactly one method for specifying the default debhelper compat level of the package. Whenever possible, the debhelper-compat build-dependency is recommended.

If needed be, the DH_COMPAT environment variable can be used to override the compat level for a given command. The feature is mostly useful for either temporarily upgrading a few commands to a new compat level or keeping a few commands on a lower compat level. The feature is best used sparingly as it effectively introduces special-cases into the debian/rules file that may be surprising to maintainers or reviewers (or, in the long term, to yourself).

Unless otherwise indicated, all debhelper documentation assumes that you are using the most recent compatibility level, and in most cases does not indicate if the behavior is different in an earlier compatibility level, so if you are not using the most recent compatibility level, you're advised to read below for notes about what is different in earlier compatibility levels.

### Supported compatibility levels
The list of supported compatibility levels and the related upgrade check list has moved to debhelper-compat-upgrade-checklist(7).

## NOTES

### Multiple binary package support
If your source package generates more than one binary package, debhelper programs will default to acting on all binary packages when run. If your source package happens to generate one architecture dependent package, and another architecture independent package, this is not the correct behavior, because you need to generate the architecture dependent packages in the binary-arch debian/rules target, and the architecture independent packages in the binary-indep debian/rules target.

To facilitate this, as well as give you more control over which packages are acted on by debhelper programs, all debhelper programs accept the -a, -i, -p, and -s parameters. These parameters are cumulative. If none are given, debhelper programs default to acting on all packages listed in the control file, with the exceptions below.

First, any package whose Architecture field in debian/control does not match the DEB_HOST_ARCH architecture will be excluded ("Debian Policy, section 5.6.8").

Also, some additional packages may be excluded based on the contents of the DEB_BUILD_PROFILES environment variable and Build-Profiles fields in binary package stanzas in debian/control, according to the draft policy at <https://wiki.debian.org/BuildProfileSpec>.

Interaction between package selections and Build-Profiles

Build-Profiles affect which packages are included in the package selections mechanisms in debhelper. Generally, the package selections are described from the assumption that all packages are enabled. This section describes how the selections react when a package is disabled due to the active Build-Profiles (or lack of active Build-Profiles).

-a/--arch, -i/--indep OR no selection options (a raw "dh_X" call)

The package disabled by Build-Profiles is silently excluded from the selection. Note you will receive a warning if all packages related to these selections are disabled. In that case, it generally does not make sense to do the build in the first place.

-N package / --no-package package

The option is accepted and effectively does nothing.

-p package / --package package

The option is accepted, but debhelper will not act on the package.

Note that it does not matter whether a package is enabled or disabled by default.

### Automatic generation of Debian install scripts
Some debhelper commands will automatically generate parts of Debian maintainer scripts. If you want these automatically generated things included in your existing Debian maintainer scripts, then you need to add #DEBHELPER# to your scripts, in the place the code should be added. #DEBHELPER# will be replaced by any auto-generated code when you run dh_installdeb.

If a script does not exist at all and debhelper needs to add something to it, then debhelper will create the complete script.

When inserting the #DEBHELPER# token into a script, consider whether any of the hand written code has a compelling reason to appear before the #DEBHELPER# token. The #DEBHELPER# token will generally contain the code that start (postinst) or stop (prerm/preinst) any services the package is providing. Often (but not always), it is better to let the code from #DEBHELPER# run first. Common exceptions include things like set -e, initializing debconf (when needed) and special-cases like generation or hand-written management of configuration files. These things should generally occur before the #DEBHELPER# token.

All debhelper commands that automatically generate code in this way let it be disabled by the -n parameter (see above).

Note that the inserted code will be shell code, so you cannot directly use it in a Perl script. If you would like to embed it into a Perl script, here is one way to do that (note that I made sure that $1, $2, etc are set with the set command):

```
  my $temp="set -e\nset -- @ARGV\n" . << 'EOF';
  #DEBHELPER#
  EOF
  if (system($temp)) {
     my $exit_code = ($? >> 8) & 0xff;
     my $signal = $? & 0x7f;
     if ($exit_code) {
         die("The debhelper script failed with error code: ${exit_code}");
     } else {
         die("The debhelper script was killed by signal: ${signal}");
     }
  }
```

### Automatic generation of miscellaneous dependencies.
Some debhelper commands may make the generated package need to depend on some other packages. For example, if you use dh_installdebconf(1), your package will generally need to depend on debconf. Or if you use dh_installxfonts(1), your package will generally need to depend on a particular version of xutils. Keeping track of these miscellaneous dependencies can be annoying since they are dependent on how debhelper does things, so debhelper offers a way to automate it.

As of compat 14, debhelper will automatically inject the relevant dependencies for you, since the dependency is done via a "relationship substvar" (see <https://lists.debian.org/debian-devel/2024/02/msg00230.html> and <https://lists.debian.org/debian-devel/2024/03/msg00030.html> for details).

In earlier compat levels, you have to manually specify the relevant substvars in the relevant fields. Typically, ${misc:Depends} for the Depends field and ${misc:Pre-Depends} for the Pre-Depends fields.

The variables listed here are entirely independent of the standard ${shlibs:Depends} generated by dh_makeshlibs(1), and the ${perl:Depends} generated by dh_perl(1). For compat 13 and earlier you will also have to add these to the respective fields when relevant.

### Package build directories
By default, all debhelper programs assume that the temporary directory used for assembling the tree of files in a package is debian/package.

Sometimes, you might want to use some other temporary directory. This is supported by the -P flag. For example, "dh_installdocs -Pdebian/tmp", will use debian/tmp as the temporary directory. Note that if you use -P, the debhelper programs can only be acting on a single package at a time. So if you have a package that builds many binary packages, you will need to also use the -p flag to specify which binary package the debhelper program will act on.

### udebs
Debhelper includes support for udebs. To create a udeb with debhelper, add "Package-Type: udeb" to the package's stanza in debian/control. Debhelper will try to create udebs that comply with debian-installer policy, by making the generated package files end in .udeb, not installing any documentation into a udeb, skipping over preinst, postrm, prerm, and config scripts, etc.

## ENVIRONMENT
This section describes some of the environment variables that influences the behaviour of debhelper or which debhelper interacts with.

It is important to note that these must be actual environment variables in order to affect the behaviour of debhelper (not simply Makefile variables). To specify them properly in debian/rules, be sure to "export" them. For example, "export DH_VERBOSE".

DH_VERBOSE

Set to a non-empty value to enable verbose mode. Please see the -v / --verbose option for details.

DH_QUIET

Set to a non-empty value to enable quiet mode. Debhelper will not output commands calling the upstream build system nor will dh print which subcommands are called and depending on the upstream build system might make that more quiet, too. This makes it easier to spot important messages but makes the output quite useless as buildd log. Ignored if DH_VERBOSE is also set or -v / --verbose is passed.

DH_COMPAT

Temporarily specifies what compatibility level debhelper should run at, overriding the default compat level of the source package.

DH_NO_ACT

Set to 1 to enable no-act mode.

DH_OPTIONS

All debhelper tools will parse command line arguments listed in this variable before any command option (as if they had been prepended to the command line arguments). Unfortunately, some third-party provided tools may not support this variable and will ignore these command line arguments. When using dh(1), it can be passed options that will be passed on to each debhelper command, which is generally better than using DH_OPTIONS.

DH_ALWAYS_EXCLUDE

If set, this adds the value the variable is set to to the -X options of all commands that support the -X option. Moreover, dh_builddeb will rm -rf anything that matches the value in your package build tree. This can be useful if you are doing a build from a CVS source tree, in which case setting DH_ALWAYS_EXCLUDE=CVS will prevent any CVS directories from sneaking into the package you build. Or, if a package has a source tarball that (unwisely) includes CVS directories, you might want to export DH_ALWAYS_EXCLUDE=CVS in debian/rules, to make it take effect wherever your package is built.

Multiple things to exclude can be separated with colons, as in DH_ALWAYS_EXCLUDE=CVS:.svn

DH_EXTRA_ADDONS

If set, this adds the specified dh addons to be run in the appropriate places in the sequence of commands. This is equivalent to specifying the addon to run with the --with flag in the debian/rules file. Any --without calls specifying an addon in this environment variable will not be run. This is intended to be used by downstreams or specific local configurations that require a debhelper addon to be run during multiple builds without having to patch a large number of rules file. If at all possible, this should be avoided in favor of a --with flag in the rules file.

DH_COLORS, DPKG_COLORS

These variables can be used to control whether debhelper commands should use colors in their textual output. Can be set to "always", "auto" (the default), or "never". Note that DPKG_COLOR also affects a number of dpkg related tools and debhelper uses it on the assumption that you want the same color setting for dpkg and debhelper. In the off-hand chance you want different color setting for debhelper, you can use DH_COLORS instead or in addition to DPKG_COLORS.

NO_COLOR

If no explicit request for color has been given (e.g. DH_COLORS and DPKG_COLORS are both unset), the presence of this environment variable cause the default color setting to be "never". The variable is defined according to <https://no-color.org/>. In this project, the environment variables (such as DH_COLORS) are considered an explicit request for color.

CFLAGS, CPPFLAGS, CXXFLAGS, OBJCFLAGS, OBJCXXFLAGS, GCJFLAGS, FFLAGS, FCFLAGS, LDFLAGS

By default (in any non-deprecated compat level), debhelper will automatically set these flags by using dpkg-buildflags(1), when they are unset. If you need to change the default flags, please use the features from dpkg-buildflags(1) to do this (e.g. DEB_BUILD_MAINT_OPTIONS=hardening=all or DEB_CPPFLAGS_MAINT_APPEND=-DCUSTOM_MACRO=true) rather than setting the concrete variable directly.

HOME, XDG_*

In compat 13 and later, these environment variables are reset before invoking the upstream build system via the dh_auto_* helpers. The variables HOME (all dh_auto_* helpers) and XDG_RUNTIME_DIR (dh_auto_test only) will be set to a writable directory. All remaining variables and XDG_RUNTIME_DIR (except for during dh_auto_test) will be cleared. The HOME directory will be created as an empty directory but it will be reused between calls to dh_auto_*. Any content will persist until explicitly deleted or dh_clean.

DEB_BUILD_OPTIONS

Please see "Supported flags in DEB_BUILD_OPTIONS" for this environment variable. Please note that this variable should not be altered by package maintainers inside debian/rules to change the behaviour of debhelper. Instead, where the package maintainer need these features, they should look disabling the relevant feature directly (e.g. by overriding the concrete tools).

DEB_BUILD_MAINT_OPTIONS

This is a dpkg specific environment variable (see e.g. dpkg-buildflags(1)). The debhelper tool suite silently ignores it. It is documented here because it has a similar name to DEB_BUILD_OPTIONS, which make some people mistakenly assume that debhelper will also react to this variable.

### Supported flags in DEB_BUILD_OPTIONS
The debhelper tool suite reacts to the following flags in DEB_BUILD_OPTIONS.

dherroron=obsolete-compat-levels

This is a debhelper specific value. When dherroron is present and set to obsolete-compat-levels, then debhelper tools will promote deprecation warnings for usage of old soon to be removed compat levels into errors.

This is useful for automated checking for code relying on deprecated compat levels that is scheduled for removal.

This option is intended for testing purposes; not production builds.

nostrip

This value will change the content of the debs being built. The .deb packages built when this is set is therefore not bit-for-bit reproducible with a regular build in the general case. This value will cause the official debhelper tools will skip actions and helpers that either remove, detach or deduplicate debugging symbols in ELF binaries.

This value affects dh_dwz(1) and dh_strip(1).

nocheck

This value will cause the official debhelper build systems to skip runs of upstream test suites. Package maintainers looking to avoid running the upstream tests should not rely on this. Instead, they can add an empty override target to skip dh_auto_test.

This value affects dh_auto_test(1).

nodoc

This value will change the content of the debs being built. The .deb packages built when this is set is therefore not bit-for-bit reproducible with a regular build in the general case. This value will cause several debhelper tools to skip installation of documentation such as manpages or upstream provided documentation. Additionally, the tools will also ignore if declared documentation is "missing" on the assumption that the documentation has not been built.

This value effects tools like dh_installdocs(1), which knows it is working with documentation.

notrimdch

This value will change the content of the debs being built. The .deb packages built when this is set is therefore not bit-for-bit reproducible with a regular build in the general case. This value will cause dh_installchangelogs(1) to act as if it had been passed the --no-trim option, forcing it to forgo removing older entries from changelogs.

noautodbgsym, noddebs

The official name is noautodbgsym. The noddebs variant is accepted for historical reasons. This value causes debhelper to skip the generation of automatically generated debug symbol packages.

This value affects dh_strip(1).

parallel=N

This value enables debhelper to use up to N threads or processes (subject to parameters like --no-parallel and --max-parallel=M). Not all debhelper tools work with parallel tasks and may silently ignore the request. This value affects many debhelper tools. Most notably dh_auto_*, which will attempt to run the underlying upstream build system with that number of threads.

terse

This value will cause the official debhelper build systems to configure upstream builds to be terse (i.e. reduce verbosity in their output). This is subject to the upstream and the debhelper build system supporting such features. This value affects most dh_auto_* tools directly. For commands provided by the debhelper package, it also causes the tools to act like the DH_QUIET environment variable was non-empty.

Unknown flags are silently ignored.

Note third-party debhelper-like tools or third-party provided build systems may or may not react to the above flags. This tends to depend on implementation details of the tool.

## SEE ALSO
debhelper-compat-upgrade-checklist(7)

List of supported compat levels and an upgrade checklist for each of them.

/usr/share/doc/debhelper/examples/

A set of example debian/rules files that use debhelper.

<http://joeyh.name/code/debhelper/>

Debhelper web site.

## AUTHOR
Joey Hess <joeyh@debian.org>


debhelper-compat-upgrade-checklist

title: debhelper-compat-upgrade-checklist(7)

text:
# debhelper-compat-upgrade-checklist(7)

## NAME
debhelper-compat-upgrade-checklist - Upgrade checklist for supported debhelper compat levels

## SYNOPSIS
This document is an upgrade checklist of all the supported debhelper compat levels. It also lists all the supported debhelper compat levels.

The dh_assistant compat-upgrade-checklist command can provide a package specific upgrade checklist from compat 7 and up (requires debhelper/13.25 or later). Its main limitation is accuracy of its heuristics. Please review the documentation of dh_assistant(1) for details.

Information about how to declare the compat level is in "COMPATIBILITY LEVELS" in debhelper(7).

If you are upgrading from a (now) obsolete compat level, then please refer to debhelper-obsolete-compat(7).

## DESCRIPTION

### Upgrade checklist for supported compatibility levels
These are the available compatibility levels:

v15

This compatibility level is still open for development; use with caution. Changes from v14 are:

- The single-binary add-on for dh is no longer implicitly activated by source packages that have a single Package stanza in debian/control. If the package needs the short-cuts for single-binary packages, it must explicitly activate the single-binary add-in. This can be done via a Build-Depends on dh-sequence-single-binary.

Any --without single-binary passed to dh to avoid the warning in compat 14 can now be removed to simplify debian/rules without triggering the warning.

- It is now an error to use package-less versions of debhelper configuration files when there are 2 or more binary packages listed in debian/control in most cases. Legacy files should be renamed to debian/package.foo (from debian/foo) where package is the first binary package listed in debian/control. The primary exception to this change are files such as debian/changelog, debian/NEWS, and debian/copyright, where the same file is used for all packages by default. These cases will remain unchanged.

- It is now an error to use a packaging file without the package prefix for --name even if the source package only produces one binary package. As example, if you had a debian/bar.service with the following snippet in debian/rules:

```
 override_dh_installsystemd:
    dh_installsystemd -p foo --name bar

```

Then you need to rename debian/bar.service to debian/foo.bar.service.

v14

This compatibility level is still open for development; use with caution. Changes from v13 are:

- The dh_installmodules and dh_installpam tools will now install their configuration files under /usr/lib/modprobe.d/package and /usr/lib/pam.d/package instead of their respective directory under /etc. Please consider using the "rm_conffile" feature from dh_installdeb(1) to ensure the proper removal of previous modprobe and PAM files.

- Packages using the dh sequencer should be aware the following changes:

- The order and placement has changed for dh_strip_nondeterminism, dh_compress, and dh_fixperm. Previously, these three commands were run in the listed order between dh_installxfonts and dh_missing. Their new placement is after dh_missing (arch:all) or dh_shlibdeps (arch:any) and before dh_installdeb. Additionally, their new order is dh_fixperms, dh_strip_nondeterminism, and then dh_compress.

This change may require updates to third-party add-ons that use either of these three commands as anchor or to hook targets for any of these commands that made assumptions about the command order.

Additionally, dh_strip_nondeterminism and dh_compress plus any commands added by third-party add-ons using these as anchors will no longer be able to rely on the mode/ownership normalization by dh_fixperms, which may expose bugs in the form of incorrect mode or ownership in the resulting binary package.

Please file any such bugs against the relevant tool. Feel free to include the debhelper maintainers in CC.

- The tool dh_installsysusers is now included in the default sequence. This helper tool will process systemd sysusers files.

- The dh_installalternatives tool will now be run after dh_link rather than after dh_installinitramfs in the default dh sequence.

- The dh_dwz command has been removed from the default sequence. If it is still desired, add dh-sequence-dwz to Build-Depends-Arch or run it in execute_before_dh_strip-arch with -a to get the closest emulation of the previous behavior. Note: The dh_dwz command will cause a lot of differences in the generated debug symbols. If you use diffoscope as part of your compat upgrade checks, you may want to temporarily use dh_dwz to keep the delta reviewable while upgrading and then remove dh_dwz afterwards.

- Use of the dh_gconf command in override and hook targets now causes an error. The dh_gconf command has been a no-op for years and was removed in debhelper 13.4.

- A new tool called dh_computeautosubstvars has been added and is now run immediately before dh_gencontrol. If you inject commands before dh_gencontrol (either via hook targets or third-party sequence add-on), consider moving them to after dh_installdeb instead as the new tool generally assumes no more changes will occur between it is called and dh_gencontrol is called. Notable exception to this assumption if you have to tweak substvars per <https://lists.debian.org/debian-devel/2024/03/msg00030.html>.

- This item only applies to source packages that have exactly one Package stanza in debian/control. The dh_auto_install command now unconditionally uses --destdir=debian/tmp by default. The special-case for source packages building a single binary package is now moved to single-binary dh addon. Note, this add-on is activated by default in compat 14 but not in compat 15 (see next bullet item).

- This item only applies to source packages that have exactly one Package stanza in debian/control. The dh sequencer will warn if the single-binary addon is implicitly activated to warn maintainers of the pending compat 15 change in dh_auto_install. The implicit activation is a transitional feature to reduce the changes of risks with this change. In compat 15, the implicit activation will no longer trigger.

Maintainers are urged to either explicitly activate the single-binary addon to preserve the existing behaviour (e.g., by adding dh-sequence-single-binary to Build-Depends), or explicitly passing --destdir to dh_auto_install if used and then passing --without single-binary to dh (the latter to silence the warning).

The rationale for this change is to avoid "surprises" when adding a second binary package later. Previously, debhelper would silently change behaviour often resulting in empty binary packages being uploaded to the archive by mistake. With the new behaviour, the single-binary addon will detect the mismatch and warn the maintainer of what is about to happen.

- The dh_installsystemduser tool will default to enabling systemd user units, start them on installation, restart them on upgrades and stop them on uninstalling the package.

- The dh_gencontrol tool now automatically applies relationship substvars to relevant fields. That means that many substvars such as ${misc:Depends} and ${shlibs:Depends} no longer need to be explicitly mentioned in debian/control. This applies to any substvar named after a field that the installed version of dpkg considers a relation or dependency-like field. At the time of writing, the list consists of:

- Pre-Depends

- Depends

- Recommends

- Suggests

- Enhances

- Conflicts

- Breaks

- Replaces

- Provides

- Built-Using

- Static-Built-Using

This means that Depends: foo, ${misc:Depends} in debian/control can now be reduced to Depends: foo and Depends: ${misc:Depends}, ${shlibs:Depends} can be removed entirely as examples of how the feature works.

Note that other substvars such as ${binary:Version} are unaffected by this change and should still be used explicitly as necessary. Additionally, for Essential: yes packages that manually promoted ${shlibs:Depends} into Pre-Depends field, dh_shlibdeps will handle this automatically as well (see the next compat item).

See <https://lists.debian.org/debian-devel/2024/02/msg00230.html> for the details of this proposal. The summary in <https://lists.debian.org/debian-devel/2024/03/msg00030.html> also covers when the substvars need tweaking. The most common case involves using the -d option from dpkg-shlibdeps possibly via dh_shlibdeps.

Note: This change will cause false-positives from an unfixed lintian(1). Please check <https://bugs.debian.org/1067653> for lintian(1) support for this change.

Finally, debhelper also applies this feature the substvars for the following fields due to implementation details:

-

Commands See #638517 <https://bugs.debian.org/638517> for what the field is used for.

- The dh_shlibdeps tool now defaults to using ${shlibs:Pre-Depends} for packages that are Essential: yes. Note due to the dh_gencontrol change above, any package using dh_gencontrol will not have to do anything for this migration.

- When running dh_auto_install, debhelper provided build systems will now ensure all paths in the destdir have minimal user permissions (chmod -R u+rwX) to avoid weird permission denied errors during builds. Third-party provided debhelper build systems are recommended to support this as well. This can be done by running

```
     $this->ensure_minimal_permissions($destdir) if not compat(13);

```

in the debhelper Buildsystem code from their sub install implementation after the upstream code has been run.

If you are not using dh_auto_install and you run into weird permission denied errors, you can often solve this by running chmod -R u+rwX DIRECTORY after running the install target from the upstream build system.

Please take care to check if your package has any special cases for permissions where files or directories for some reason must not have the "user write bit" set. Known cases are *.ali files and /etc/sudoers.d, which dh_fixperms will fix up by default.

The problem with uncommon permissions have always been present in theory. However, it has become considerable more visible with dh_fixperms being run later in the sequence as of compat 14 and with the move to remove fakeroot by default (which papered over some of these issues). This change is aimed at mitigating the problem.

- The debhelper configuration files are subject to the following changes:

- It now triggers a warning to use package-less versions of debhelper configuration files when there are 2 or more binary packages listed in debian/control in most cases. Legacy files should be renamed to debian/package.foo (from debian/foo) where package is the first binary package listed in debian/control. The primary exception to this change are files such as debian/changelog, debian/NEWS, and debian/copyright, where the same file is used for all packages by default. These cases will remain unchanged. The debhelper tool using the files will trigger warnings on usage.

In compat 15 (or later), this is changed to an error.

For most packages, this item can be fixed by running:

```
     apt-get satisfy 'debputy (>= 0.1.73~), debhelper (>= 13.26~)'
     debputy migrate-from-dh --migration-target=dh-package-prefixed-config-files

```

The only known caveat are architecture specific configuration files (such as debian/symbols.amd64 or debian/install.amd64).

- It now triggers a warning to use a packaging file without the package prefix for --name even if the source package only produces one binary package. As example, if you had a debian/bar.service with the following snippet in debian/rules:

```
 override_dh_installsystemd:
    dh_installsystemd -p foo --name bar

```

Then you need to rename debian/bar.service to debian/foo.bar.service.

In compat 15 (or later), this is changed to an error.

For most packages, this item can be fixed by running:

```
     apt-get satisfy 'debputy (>= 0.1.73~), debhelper (>= 13.26~)'
     debputy migrate-from-dh --migration-target=dh-package-prefixed-config-files

```

The only known caveat are architecture specific configuration files. The debhelper stack does not accept any config files that have architecture restrictions and --name. However, third-party add-ons might.

- The default look up rules for Dh_Lib based tools now assume that configuration files are no longer named (--name) nor support architecture restrictions by default. If you work with a third-party debhelper-like tool and need support for either of these features, please file a bug against the tool asking it to declare its configuration file with the relevant options in its pkgfile call. Note that debhelper itself tweaked its rules for most of its tools as well based on analysis of usage via codesearch.debian.org. Should you be relying on a feature like architecture restrictions for a given config file that is no longer supported, please file a feature request for the use-case and it might be restored.

-

Packages using the cmake build system should be aware of the following changes:

- The cmake buildsystem now passes -DCMAKE_BUILD_RPATH_USE_ORIGIN=ON to cmake(1) to avoid some reproducibility issues.

- The cmake build system now sets the ASMFLAGS environment variable when it is unset and ASFLAGS is present. The former name (ASMFLAGS) is the name cmake expects, while the latter (ASFLAGS) is the name that dpkg-buildpackage(1) uses.

- The cmake build systems now use cmake --install instead of make install in the dh_auto_install(1) call. Any override of dh_auto_install that passes extra parameters to the upstream build system should be reviewed.

-

Packages using the meson build system should be aware of the following changes:

- The meson build system now passes --auto-features=enabled to meson.

- The meson+ninja build system now use meson install instead of ninja install in the dh_auto_install(1) call. Any override of dh_auto_install that passes extra parameters to the upstream build system should be reviewed.

- The debian/compat file is no longer accepted as a source for specifying the debhelper compat level. Please review "COMPATIBILITY LEVELS" in debhelper(7) for alternatives. Note to avoid breaking packages that already migrated to compat 14 immediately, while it was experimental this change is first enforced when compat 14 becomes stable.

- The tool dh_installtmpfiles now runs with --remove on package removal, and --purge on package purge. systemd v256 is required for the latter.

- The dh_lintian tool no longer accepts architecture specific overrides files for packages with Multi-Arch: same in debian/control, since these would not be co-installable. Instances affected by this error should migrate to lintian(1) architecture specific overrides.

- The third-party dh_qmldeps tool (from pkg-kde-tools package) no longer demote detected dependencies. In v13 you get warnings about demotions. You can use the -d dependency field in the debian/PKG.qmlfiles to get the dependencies end up in the correct dependency field.

v13

This is the recommended mode of operation. Changes from v12 are:

- The meson+ninja build system now uses meson test instead of ninja test when running the test suite. Any override of dh_auto_test that passes extra parameters to upstream test runner should be reviewed as meson test is not command line compatible with ninja test.

- All debhelper like tools based on the official debhelper library (including dh and the official dh_* tools) no longer accepts abbreviated command parameters. At the same time, dh now optimizes out calls to redundant dh_* helpers even when passed long command line options.

- The ELF related debhelper tools (dh_dwz, dh_strip, dh_makeshlibs, dh_shlibdeps) are now only run for arch dependent packages by default (i.e. they are excluded from *-indep targets and are passed -a by default). If you need them for *-indep targets, you can add an explicit Build-Depends on dh-sequence-elf-tools.

- The third-party gradle build system (from gradle-debian-helper package) now runs the upstream-provided test suite automatically. To suppress such behavior, override dh_auto_test.

- The dh_installman tool now aborts if it sees conflicting definitions of a manpage. This typically happens if the upstream build system is installing a compressed version and the package lists an uncompressed version of the manpage in debian/package.manpages. Often the easiest fix is to remove the manpage from debian/package.manpages (assuming both versions are identical).

- The dh_auto_* helpers now reset the environment variable HOME and the common XDG_* variables. Please see description of the environment variables in "ENVIRONMENT" in debhelper(1) for how this is handled. This feature changed between debhelper 13 and debhelper 13.2.

- The dh command will now error if an override or hook target for an obsolete command are present in debian/rules (e.g. override_dh_systemd_enable:).

- The dh_missing command will now default to --fail-missing. This can be reverted to a non-fatal warning by explicitly passing --list-missing like it was in compat 12. If you do not want the warning either, please omit the call to dh_missing. If you use the dh command sequencer, then you can do this by inserting an empty override target in the debian/rules file of the relevant package. As an example:

```
    # Disable dh_missing
    override_dh_missing:

```

- The dh command sequencer now runs dh_installtmpfiles in the default sequence. The dh_installtmpfiles takes over handling of tmpfiles.d configuration files. Related functionality in dh_installsystemd is now disabled. Note that dh_installtmpfiles responds to debian/package.tmpfiles where dh_installsystemd used a name without the trailing "s".

- Many dh_* tools now support limited variable expansion via the ${foo} syntax. In many cases, this can be used to reference paths that contain either spaces or dpkg-architecture(1) values. While this can reduce the need for dh-exec(1) in some cases, it is not a replacement dh-exec(1) in general. If you need filtering, renaming, etc., the package will still need dh-exec(1). Please see "Substitutions in debhelper config files" for syntax and available substitution variables. To dh_* tool writers, substitution expansion occurs as a part of the filearray and filedoublearray functions.

- The dh command sequencer will now skip all hook and override targets for dh_auto_test, dh_dwz and dh_strip when DEB_BUILD_OPTIONS lists the relevant nocheck / nostrip options. Any package relying on these targets to always be run should instead move relevant logic out of those targets. E.g. non-test related packaging code from override_dh_auto_test would have to be moved to execute_after_dh_auto_build or execute_before_dh_auto_install.

- The cmake buildsystem now passes -DCMAKE_SKIP_INSTALL_ALL_DEPENDENCY=ON to cmake(1) to speed up automatic installation process. If for some reason you need previous behavior, override the flag:

```
    dh_auto_configure -- -DCMAKE_SKIP_INSTALL_ALL_DEPENDENCY=OFF ...

```

v12

Changes from v11 are:

- The dh_makeshlibs tool now generates shlibs files with versioned dependency by default. This means that -VUpstream-Version (a.k.a. -V) is now the default. If an unversioned dependency in the shlibs file is wanted, this can be obtained by passing -VNone instead. However, please see dh_makeshlibs(1) for the caveat of unversioned dependencies.

- The -s (--same-arch) option is removed. Please use -a (--arch) instead.

- Invoking dh_clean -k now causes an error instead of a deprecation warning.

- The --no-restart-on-upgrade option in dh_installinit has been removed. Please use the new name --no-stop-on-upgrade

- There was a bug in the doit (and similar) functions from Debian::Debhelper::Dh_Lib that made them spawn a shell in one particular circumstance. This bug is now removed and will cause helpers that rely on the bug to fail with a "command not found"-error.

- The --list-missing and --fail-missing in dh_install has been removed. Please use dh_missing and its corresponding options, which can also see the files installed by other helpers.

- The dh_installinit helper no longer installs configuration for the upstart init system. Instead, it will abort the build if it finds an old upstart configuration file. The error is there to remind the package maintainer to ensure the proper removal of the conffiles shipped in previous versions of the package (if any).

- The dh_installdeb tool will do basic validation of some dpkg-maintscript-helper(1) commands and will error out if the commands appear to be invalid.

- The dh_missing tool will now default to --list-missing.

- The dh_makeshlibs tool will now only pass libraries to dpkg-gensymbols(1) if the ELF binary has a SONAME (containing ".so").

- The dh_compress tool no longer compresses examples (i.e. anything installed in </usr/share/doc/package/examples>.)

- The standard sequence in dh now includes dh_dwz and dh_installinitramfs by default. This makes the dwz and installinitramfs sequences obsolete and they will now fail with an error. If you want to skip these commands, then please insert an empty override target for them in debian/rules (e.g. override_dh_dwz:)

- The build systems meson and autoconf no longer explicitly set the --libexecdir variable and thus relies on the build system default - which should be /usr/libexec (per FHS 3.0, adopted in Debian Policy 4.1.5). If a particular upstream package does not use the correct default, the parameter can often be passed manually via dh_auto_configure(1). E.g. via the following example:

```
    override_dh_auto_configure:
        dh_auto_configure -- --libexecdir=/usr/libexec

```

Note the -- before the --libexecdir parameter.

- Retroactively removed in debhelper/13.5: The dh_installdeb tool would no longer install the maintainer provided conffiles file as it was deemed unnecessary. However, the remove-on-upgrade from dpkg/1.20 made the file relevant again and dh_installdeb now installs it again in compat levels 12+.

- The dh_installsystemd tool no longer relies on dh_installinit for handling systemd services that have a sysvinit alternative. Both tools must now be used in such a case to ensure the service is properly started under both sysvinit and systemd. If you have an override for dh_installinit (e.g. to call it with --no-start) then you will probably need one for dh_installsystemd as well now.

This change makes dh_installinit inject a misc:Pre-Depends for init-system-helpers (>= 1.54~). Please ensure that the package lists ${misc:Pre-Depends} in its Pre-Depends field before upgrading to compat 12.

- The third-party dh_golang tool (from dh-golang package) now defaults on honoring DH_GOLANG_EXCLUDES variable for source installation in -dev packages and not only during the building process. Please set DH_GOLANG_EXCLUDES_ALL to false to revert to the previous behaviour. See Debian::Debhelper::Buildsystem::golang(3pm) for details and examples.

- dh_installsystemduser is now included in the dh standard sequence by default.

- The python-distutils buildsystem is now removed. Please use the third-party build system pybuild instead.

v11

This mode is discouraged. The compat 11 is discouraged for new packages as it suffers from feature interaction between dh_installinit and dh_installsystemd causing services to not run correctly in some cases. Please consider using compatibility mode 10 or 12 instead. More details about the issue are available in Debian#887904 and <https://lists.debian.org/debian-release/2019/04/msg01442.html>.

Changes from v10 are:

- dh_installinit no longer installs service or tmpfile files, nor generates maintainer scripts for those files. Please use the new dh_installsystemd helper.

- The dh_systemd_enable and dh_systemd_start helpers have been replaced by the new dh_installsystemd helper. For the same reason, the systemd sequence for dh has also been removed. If you need to disable the dh_installsystemd helper tool, please use an empty override target. Please note that the dh_installsystemd tool has a slightly different behaviour in some cases (e.g. when using the --name parameter).

- dh_installdirs no longer creates debian/package directories unless explicitly requested (or it has to create a subdirectory in it). The vast majority of all packages will be unaffected by this change.

- The makefile buildsystem now passes INSTALL="install --strip-program=true" to make(1). Derivative buildsystems (e.g. configure or cmake) are unaffected by this change.

- The autoconf buildsystem now passes --runstatedir=/run to ./configure.

- The cmake buildsystem now passes -DCMAKE_INSTALL_RUNSTATEDIR=/run to cmake(1).

- dh_installman will now prefer detecting the language from the path name rather than the extension.

- dh_auto_install will now only create the destination directory it needs. Previously, it would create the package build directory for all packages. This will not affect packages that only build with debhelper commands, but it may expose bugs in commands not included in debhelper.

- The helpers dh_installdocs, dh_installexamples, dh_installinfo, and dh_installman now error out if their config has a pattern that does not match anything or reference a path that does not exist. Known exceptions include building with the nodoc profile, where the above tools will silently permit failed matches where the patterns are used to specify documentation.

- The helpers dh_installdocs, dh_installexamples, dh_installinfo, and dh_installman now accept the parameter --sourcedir with same meaning as dh_install. Furthermore, they now also fall back to debian/tmp like dh_install. Migration note: A bug in debhelper 11 up to 11.1.5 made dh_installinfo incorrectly ignore --sourcedir.

- The perl-makemaker and perl-build build systems no longer pass -I. to perl. Packages that rely on this behavior can often use the PERL5LIB environment variable as a substitute. E.g. by adding export PERL5LIB=. in their debian/rules file (or similar).

- The PERL_USE_UNSAFE_INC environment variable is no longer set by dh or any of the dh_auto_* tools. It was added as a temporary work around to avoid a lot of packages failing to build at the same time. Note this item will eventually become obsolete as upstream intends to drop support for the PERL_USE_UNSAFE_INC environment variable. When perl drops support for it, then this variable will be removed retroactively from existing compat levels as well.

- The dh_makeshlibs helper will now exit with an error if objdump returns a non-zero exit from analysing a given file.

- The dh_installdocs and dh_installexamples tools may now install most of the documentation in a different path to comply with the recommendation from Debian policy §12.3 (since version 3.9.7). Note that if a given source package only contains a single binary package in debian/control or none of the packages are -doc packages, then this change is not relevant for that source package and you can skip to the next change.

By default, these tools will now attempt to determine a "main package for the documentation" (called a doc-main-package from here on) for every -doc package. If they find such a doc-main-package, they will now install the documentation into the path /usr/share/doc/doc-main-package in the given doc package. I.e. the path can change but the documentation is still shipped in the -doc package.

The --doc-main-package option (or, since debhelper/13.28, the X-Doc-Main-Package field) can be used when the auto-detection is insufficient or to reset the path to its previous value if there is a reason to diverge from Debian policy recommendation.

Some documentation will not be affected by this change. These exceptions include the copyright file, changelog files, README.Debian, etc. These files will still be installed in the path /usr/share/doc/package.

- The dh_strip and dh_shlibdeps tools no longer uses filename patterns to determine which files to process. Instead, they open the file and look for an ELF header to determine if a given file is an shared object or an ELF executable. This change may cause the tools to process more files than previously.

v10

Changes from v9 are:

- dh_installinit will no longer installs a file named debian/package as an init script.

- dh_installdocs will error out if it detects links created with --link-doc between packages of architecture "all" and non-"all" as it breaks binNMUs.

- dh_installdeb no longer installs a maintainer-provided debian/package.shlibs file. This is now done by dh_makeshlibs instead.

- dh_installwm refuses to create a broken package if no man page can be found (required to register for the x-window-manager alternative).

- Debhelper will default to --parallel for all buildsystems that support parallel building. This can be disabled by using either --no-parallel or passing --max-parallel with a value of 1.

- The dh command will not accept any of the deprecated "manual sequence control" parameters (--before, --after, etc.). Please use override targets instead. Retroactively applied to earlier compat levels: dh no longer accepts any of these since debhelper/12.4.

- The dh command will no longer use log files to track which commands have been run. The dh command still keeps track of whether it already ran the "build" sequence and skip it if it did. The main effects of this are:

- With this, it is now easier to debug the install or/and binary sequences because they can now trivially be re-run (without having to do a full "clean and rebuild" cycle)

- The main caveat is that dh_* now only keeps track of what happened in a single override target. When all the calls to a given dh_cmd command happens in the same override target everything will work as before. Example of where it can go wrong:

```
  override_dh_foo:
    dh_foo -pmy-pkg
  override_dh_bar:
    dh_bar
    dh_foo --remaining

```

In this case, the call to dh_foo --remaining will also include my-pkg, since dh_foo -pmy-pkg was run in a separate override target. This issue is not limited to --remaining, but also includes -a, -i, etc.

- The dh_installdeb command now shell-escapes the lines in the maintscript config file. This was the original intent but it did not work properly and packages have begun to rely on the incomplete shell escaping (e.g. quoting file names).

- The dh_installinit command now defaults to --restart-after-upgrade. For packages needing the previous behaviour, please use --no-restart-after-upgrade.

- The autoreconf sequence is now enabled by default. Please pass --without autoreconf to dh if this is not desirable for a given package

- The systemd sequence is now enabled by default. Please pass --without systemd to dh if this is not desirable for a given package.

- Retroactively removed: dh no longer creates the package build directory when skipping running debhelper commands. This will not affect packages that only build with debhelper commands, but it may expose bugs in commands not included in debhelper. This compatibility feature had a bug since its inception in debhelper/9.20130516 that made it fail to apply in compat 9 and earlier. As there has been no reports of issues caused by this bug in those ~5 years, this item have been removed rather than fixed.

v9

Changes from v8 are:

- Multiarch support. In particular, dh_auto_configure passes multiarch directories to autoconf in --libdir and --libexecdir.

- dh is aware of the usual dependencies between targets in debian/rules. So, "dh binary" will run any build, build-arch, build-indep, install, etc targets that exist in the rules file. There's no need to define an explicit binary target with explicit dependencies on the other targets.

- dh_strip compresses debugging symbol files to reduce the installed size of -dbg packages.

- dh_auto_configure does not include the source package name in --libexecdir when using autoconf.

- dh does not default to enabling --with=python-support (Obsolete: As the dh_pysupport tool was removed from Debian stretch. Since debhelper/10.3, dh no longer enables this sequence add-on regardless of compat level)

- All of the dh_auto_* debhelper programs and dh set environment variables listed by dpkg-buildflags, unless they are already set.

- dh_auto_configure passes dpkg-buildflags CFLAGS, CPPFLAGS, and LDFLAGS to perl Makefile.PL and Build.PL

- dh_strip puts separated debug symbols in a location based on their build-id.

- Executable debhelper config files are run and their output used as the configuration.

This mode is deprecated.

v8

Changes from v7 are:

- Commands will fail rather than warning when they are passed unknown options.

- dh_makeshlibs will run dpkg-gensymbols on all shared libraries that it generates shlibs files for. So -X can be used to exclude libraries. Also, libraries in unusual locations that dpkg-gensymbols would not have processed before will be passed to it, a behavior change that can cause some packages to fail to build.

- dh requires the sequence to run be specified as the first parameter, and any switches come after it. Ie, use "dh $@ --foo", not "dh --foo $@".

- dh_auto_* prefer to use Perl's Module::Build in preference to Makefile.PL.

This mode is deprecated.

v7

This mode is deprecated. This is the lowest supported compatibility level.

If you are upgrading from an earlier compatibility level, please review debhelper-obsolete-compat(7).

## SEE ALSO
debhelper-obsolete-compat(7)

Upgrading from a (now) obsolete compatibility level? This document covers the upgrade checklist up to the earliest supported level.

debhelper(7)

General information about the debhelper framework. This document also covers how to declare your chosen debhelper compat level.

## AUTHORS
Niels Thykier <niels@thykier.net>

Joey Hess

branch: sisyphus